This thesis, "The Properties of Random Surfaces of Significance in Their Contact," by D. J. Whitehouse, submitted to the University of Leicester for a Doctor of Philosophy degree in February 1971, focuses on the understanding of surface texture and its impact on the functioning of engineering elements, particularly in stationary and sliding contact. The work bridges the gap between surface contact studies and methods of surface specification and characterization, emphasizing random surfaces produced by modern manufacturing methods. The thesis uses theories from the study of random processes to analyze surface profiles as random signals, developing a theory of movement over such profiles and examining friction and wear through experimental data. It also explores the generation of random surfaces and provides a fundamental analysis to classify surfaces based on their functional behavior and generation details. Key aspects include: - **Surface Topography and Contact:** Discusses the importance of surface finish in modern technology and the challenges in measuring and classifying surface geometry. - **Techniques:** Describes the use of stylus instruments, including the Talysurf and Talystep, and the digital techniques for analyzing surface profiles. - **Random Signal Model:** Introduces a model where a surface profile is represented as a random signal with Gaussian height distribution and exponential autocorrelation, and analyzes its significance in surface contact. - **Experimental Analysis:** Examines the movement of bodies on random surfaces and the consequences of rubbing under load, supported by experimental results. - **Surface Generation:** Investigates the mechanical methods for generating random surfaces and the theoretical basis for their characteristics. The thesis aims to provide a comprehensive understanding of the relationship between surface texture and functional behavior, particularly in contact and wear applications.This thesis, "The Properties of Random Surfaces of Significance in Their Contact," by D. J. Whitehouse, submitted to the University of Leicester for a Doctor of Philosophy degree in February 1971, focuses on the understanding of surface texture and its impact on the functioning of engineering elements, particularly in stationary and sliding contact. The work bridges the gap between surface contact studies and methods of surface specification and characterization, emphasizing random surfaces produced by modern manufacturing methods. The thesis uses theories from the study of random processes to analyze surface profiles as random signals, developing a theory of movement over such profiles and examining friction and wear through experimental data. It also explores the generation of random surfaces and provides a fundamental analysis to classify surfaces based on their functional behavior and generation details. Key aspects include: - **Surface Topography and Contact:** Discusses the importance of surface finish in modern technology and the challenges in measuring and classifying surface geometry. - **Techniques:** Describes the use of stylus instruments, including the Talysurf and Talystep, and the digital techniques for analyzing surface profiles. - **Random Signal Model:** Introduces a model where a surface profile is represented as a random signal with Gaussian height distribution and exponential autocorrelation, and analyzes its significance in surface contact. - **Experimental Analysis:** Examines the movement of bodies on random surfaces and the consequences of rubbing under load, supported by experimental results. - **Surface Generation:** Investigates the mechanical methods for generating random surfaces and the theoretical basis for their characteristics. The thesis aims to provide a comprehensive understanding of the relationship between surface texture and functional behavior, particularly in contact and wear applications.